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1.
Microsc Microanal ; 29(6): 2004-2013, 2023 Dec 21.
Article in English | MEDLINE | ID: mdl-37855685

ABSTRACT

To date, lanthanum hexaboride (LaB6) thermionic electron sources have not been able fully to capitalize on their inherent potential, resulting in an ambiguous position within the application area. Although they exhibit higher brightness compared with a tungsten filament source, they still fall short of the performance of Schottky electron sources. This study aims to explore the capabilities of the LaB6 electron source under different operating conditions to bridge the gap, ultimately to realize its untapped potential. Simulations in virtual source mode indicated enhanced beam brightness and a reduced beam half-angle with an increase the extraction voltage, promising up to tenfold times higher beam brightness compared with the crossover mode. The energy distribution measured using a prelens retarding field energy analyzer revealed an energy distribution of 0.55 eV and a high angular current density of 33 mA/sr in the virtual source mode. Therefore, the virtual source mode of LaB6 can provide a narrow energy distribution akin to that of a ZrO/W Schottky electron gun (1600 K) while having an angular current density over 2,000 times higher. In addition, the stability of the virtual source mode is ±0.022%, while that of the crossover mode is ±0.138%.

3.
ACS Appl Mater Interfaces ; 15(28): 33878-33889, 2023 Jul 19.
Article in English | MEDLINE | ID: mdl-37428956

ABSTRACT

There is growing interest in systems with randomized responses for generating physically unclonable functions (PUFs) in anticounterfeiting and authentication applications. Atomic-level control over its thickness and unique Raman spectrum make graphene an attractive material for PUF applications. Herein, we report graphene PUFs that emerge from two independent stochastic processes. Randomized variations in the shape and number of graphene adlayers were achieved by exploiting and improving the mechanistic understanding of the chemical vapor deposition of graphene. The randomized positioning of the graphene domains was then facilitated by dewetting the polymer film, followed by oxygen plasma etching. This approach yielded surfaces with randomly positioned and shaped graphene islands with varied numbers of layers and, therefore, Raman spectra. Raman mapping of surfaces resulted in multicolor images with a high encoding capacity. Advanced feature-matching algorithms were employed for the authentication of multicolor images. The use of two independent stochastic processes on a two-dimensional nanomaterial platform enables the creation of unique and complex surfaces that excessively challenge clonability.

4.
Microsc Microanal ; : 1-9, 2022 Sep 05.
Article in English | MEDLINE | ID: mdl-36062359

ABSTRACT

The energy distribution of an electron gun is one of the most important characteristics determining the performance of electron beam-based instruments, such as electron microscopes and electron energy loss spectroscopes. For accurate measurements of the energy distribution, this study presents a novel retarding field energy analyzer (RFEA) with the feature of an additional integrated pre-lens, which enables an adjustment of beam trajectory into the analyzer. The advantages of this analyzer are its compact size and simple electrode configuration. According to trajectory simulation theories, the optimum condition arises when the incident electron beam inside the RFEA is focused on the center of a retarding electrode. Comparing I­V curves depending on whether the pre-lens working or not, it is confirmed that the use of the pre-lens dramatically improves the energy resolution and efficiency of the signal acquisition process. The pre-lens RFEA was applied to characterize a Schottky electron gun under various temperatures and extraction voltages as operational conditions. When the tip temperature was increased by 50 K, we were able to measure an energy distribution broadening of 13.8 meV with the proposed pre-lens RFEA. The relative standard deviation of energy distribution was 0.7% for each working condition.

5.
Sensors (Basel) ; 21(5)2021 Mar 07.
Article in English | MEDLINE | ID: mdl-33799998

ABSTRACT

Driving environment perception for automated vehicles is typically achieved by the use of automotive remote sensors such as radars and cameras. A vehicular wireless communication system can be viewed as a new type of remote sensor that plays a central role in connected and automated vehicles (CAVs), which are capable of sharing information with each other and also with the surrounding infrastructure. In this paper, we present the design and implementation of driving environment perception based on the fusion of vehicular wireless communications and automotive remote sensors. A track-to-track fusion of high-level sensor data and vehicular wireless communication data was performed to accurately and reliably locate the remote target in the vehicle surroundings and predict the future trajectory. The proposed approach was implemented and evaluated in vehicle tests conducted at a proving ground. The experimental results demonstrate that using vehicular wireless communications in conjunction with the on-board sensors enables improved perception of the surrounding vehicle located at varying longitudinal and lateral distances. The results also indicate that vehicle future trajectory and potential crash involvement can be reliably predicted with the proposed system in different cut-in driving scenarios.

6.
Ecol Evol ; 11(1): 516-525, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33437447

ABSTRACT

Comparative studies of invasive, noninvasive alien, and native congenic plant species can identify plant traits that drive invasiveness. In particular, functional traits associated with rapid growth rate and high fecundity likely facilitate invasive success. As such traits often exhibit high phenotypic plasticity, characterizing plastic responses to anthropogenic environmental changes such as eutrophication and disturbance is important for predicting the invasive success of alien plant species in the future. Here, we compared trait expression and phenotypic plasticity at the species level among invasive, noninvasive alien, and native Bidens species. Plants were grown under nutrient addition and competition treatments, and their functional, morphological, and seed traits were examined. Invasive B. frondosa exhibited higher phenotypic plasticity in most measured traits than did the alien noninvasive B. pilosa or native B. bipinnata. However, differential plastic responses to environmental treatments rarely altered the rank of trait values among the three Bidens species, except for the number of inflorescences. The achene size of B. frondosa was larger, but its pappus length was shorter than that of B. pilosa. Two species demonstrated opposite plastic responses of pappus length to fertilization. These results suggest that the plasticity of functional traits does not significantly contribute to the invasive success of B. frondosa. The dispersal efficiency of B. frondosa is expected to be lower than that of B. pilosa, suggesting that long-distance dispersal is likely not a critical factor in determining invasive success.

7.
Biomolecules ; 10(3)2020 03 24.
Article in English | MEDLINE | ID: mdl-32213959

ABSTRACT

Prostaglandin (PG) A2, one of cyclopentenone PGs, is known to induce activation of apoptosis in various cancer cells. Although PGA2 has been reported to cause activation of apoptosis by altering the expression of apoptosis-related genes, the role of p53, one of the most critical pro-apoptotic genes, on PGA2-induced apoptosis has not been clarified yet. To address this issue, we compared the apoptosis in HCT116 p53 null cells (HCT116 p53-/-) to that in HCT116 cells containing the wild type p53 gene. Cell death induced by PGA2 was associated with phosphorylation of histone H2A variant H2AX (H2AX), activation of caspase-3 and cleavage of poly(ADP-ribose) polymerase 1 in HCT116 cells. Induction of apoptosis in PGA2-treated cells was almost completely prevented by pretreatment with a pan-caspase inhibitor, z-VAD-Fmk, or an inhibitor of protein synthesis, cycloheximide. While PGA2 induced apoptosis in HCT116 cells, phosphorylation of p53 and transcriptional induction of p53-target genes such as p21WAF1, PUMA, BAX, NOXA, and DR5 occurred. Besides, pretreatment of pifithrin-α (PFT-α), a chemical inhibitor of p53's transcriptional activity, interfered with the induction of apoptosis in PGA2-treated HCT116 cells. Pretreatment of NU7441, a small molecule inhibitor of DNA-activated protein kinase (DNA-PK) suppressed PGA2-induced phosphorylation of p53 and apoptosis as well. Moreover, among target genes of p53, knockdown of DR5 expression by RNA interference, suppressed PGA2-induced apoptosis. In the meanwhile, in HCT116 p53-/- cells, PGA2 induced apoptosis in delayed time points and with less potency. Delayed apoptosis by PGA2 in HCT116 p53-/- cells was also associated with phosphorylation of H2AX but was not inhibited by either PFT- or NU7441. Collectively, these results suggest the following. PGA2 may induce p53-dependent apoptosis in which DNA-PK activates p53, and DR5, a transcriptional target of p53, plays a pivotal role in HCT116 cells. In contrast to apoptosis in HCT116 cells, PGA2 may induce apoptosis in a fashion of less potency, which is independent of p53 and DNA-PK in HCT116 p53-/- cells.


Subject(s)
Apoptosis/drug effects , Gene Expression Regulation/drug effects , Prostaglandins A/pharmacology , Transcription, Genetic/drug effects , Tumor Suppressor Protein p53/metabolism , Apoptosis/genetics , Gene Knockout Techniques , HCT116 Cells , Humans , Phosphorylation/drug effects , Tumor Suppressor Protein p53/genetics
8.
Sensors (Basel) ; 20(1)2020 Jan 04.
Article in English | MEDLINE | ID: mdl-31947961

ABSTRACT

Driver inattention is one of the leading causes of traffic crashes worldwide. Providing the driver with an early warning prior to a potential collision can significantly reduce the fatalities and level of injuries associated with vehicle collisions. In order to monitor the vehicle surroundings and predict collisions, on-board sensors such as radar, lidar, and cameras are often used. However, the driving environment perception based on these sensors can be adversely affected by a number of factors such as weather and solar irradiance. In addition, potential dangers cannot be detected if the target is located outside the limited field-of-view of the sensors, or if the line of sight to the target is occluded. In this paper, we propose an approach for designing a vehicle collision warning system based on fusion of multisensors and wireless vehicular communications. A high-level fusion of radar, lidar, camera, and wireless vehicular communication data was performed to predict the trajectories of remote targets and generate an appropriate warning to the driver prior to a possible collision. We implemented and evaluated the proposed vehicle collision system in virtual driving environments, which consisted of a vehicle-vehicle collision scenario and a vehicle-pedestrian collision scenario.

9.
Ann Lab Med ; 34(1): 56-9, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24422197

ABSTRACT

Lung disease caused by nontuberculous mycobacteria (NTM) represents an increasing proportion of all mycobacterial diseases. We investigated recent occurrences of NTM and evaluated the clinical significance of NTM isolates from 752 respiratory specimens collected from patients at National Health Insurance Service Ilsan Hospital between January 2007 and May 2011. Specimens were incubated on solid and liquid media (BACTEC MGIT 960, BD, USA) for 6-8 weeks, and PCR and reverse blot hybridization were performed (REBA Myco-ID, Molecules & Diagnostics, Korea). Clinical features of the patients were reviewed through medical records. The most frequently isolated organism was Mycobacterium avium (46.7%), followed by M. intracellulare (14.8%), M. fortuitum (7.2%), and M. abscessus (6.6%). The most common mycobacteria among definitive cases of NTM lung disease were M. avium (42/351, 12.0%), M. intracellulare (19/111, 17.1%), M. abscessus (11/50, 22.0%), M. massiliense (4/13, 30.8%), and M. fortuitum (4/54, 7.4%). Clinically significant cases of NTM lung disease increased from 4 patients in 2007 to 32 in 2011. The mean patient age was 64 yr (range: 35-88 yr), and 58 (64%) patients were women. Patients suffered from cough, productive sputum, and hemoptysis. In summary, the most common mycobacteria causing NTM lung disease were M. avium and M. intracellulare; however, cases of M. massiliense and M. abscessus infection are on the rise in Korea.


Subject(s)
Hospitals, General/trends , Lung Diseases/microbiology , Mycobacterium Infections, Nontuberculous/microbiology , Nontuberculous Mycobacteria/physiology , Adult , Aged , Aged, 80 and over , Bronchoalveolar Lavage Fluid/microbiology , DNA, Bacterial/analysis , Female , Hospitals, General/standards , Humans , Lung Diseases/diagnosis , Male , Middle Aged , Mycobacterium Infections, Nontuberculous/diagnosis , Nontuberculous Mycobacteria/genetics , Nucleic Acid Hybridization , Polymerase Chain Reaction , Reagent Kits, Diagnostic , Republic of Korea , Sputum/microbiology
10.
Allergy Asthma Proc ; 31(4): e39-e47, 2010.
Article in English | MEDLINE | ID: mdl-20819314

ABSTRACT

Food allergies are classified as IgE-mediated food allergies (IFAs) and non-IgE-mediated food allergies (NFAs). Recently, oral immunotherapy (OIT) has been found to be successful for treating both IFA and NFA, especially using interferon (IFN) gamma. This study was designed to clarify the clinical characteristics of IFA and NFA and compare the therapeutic characteristics of OIT using subcutaneously administered IFN-gamma for both types of food allergy. In this study, 148 patients were categorized into the IFA and NFA group following food challenge, skin-prick test and food-specific IgE tests. The patients were then treated using protocols specific for IFA and NFA using subcutaneous IFN-gamma injection as a randomized controlled trial. The principle of complete allergy resolution at prior dose in the case of IFA was also evaluated. Only the patients with IFA and NFA treated with OIT using IFN-gamma achieved tolerance successfully. Tolerance was achieved from low-dose range in IFA and in high-dose range for NFA. Complete tolerance was not obtained without achieving complete allergy resolution at each dose of the allergen before increasing the dosage in IFA. Both IFA and NFA can be successfully treated with OIT using IFN-gamma but show different clinical and therapeutic characteristics. IFN-gamma is necessary for the tolerance induction but not for tolerance maintenance. Additional study for the mechanisms of tolerance induction by IFN-gamma is needed.


Subject(s)
Allergens/administration & dosage , Desensitization, Immunologic , Food Hypersensitivity/drug therapy , Hypersensitivity, Delayed/drug therapy , Interferon-gamma/therapeutic use , Adolescent , Allergens/immunology , Child , Child, Preschool , Clinical Protocols , Disease-Free Survival , Drug Therapy, Combination , Female , Food/adverse effects , Food Hypersensitivity/diagnosis , Food Hypersensitivity/immunology , Food Hypersensitivity/physiopathology , Humans , Hypersensitivity, Delayed/diagnosis , Hypersensitivity, Delayed/immunology , Hypersensitivity, Delayed/physiopathology , Immune Tolerance/drug effects , Immunoglobulin E/blood , Male , Skin Tests
11.
Allergy Asthma Proc ; 31(2): e18-24, 2010.
Article in English | MEDLINE | ID: mdl-20406588

ABSTRACT

Food allergy plays an important role in atopic dermatitis (AD). Adequate predictors and guidelines for when dietary manipulation is indicated for AD are needed. The clinical significance of eosinophilia as a predictor for food allergy of late eczematous reactions in AD was investigated. Three hundred three patients with AD were studied, using elimination diets and food challenge tests. Food allergy prevalence was compared in groups of eczematoid AD patients with high or normal eosinophil levels. The effects on the blood eosinophil fraction of an elimination diet and milk allergy provocation of late eczematous reactions were evaluated. The prevalence of food allergy was 51.1% (135/264) in patients with eczematoid AD. The major type of food allergy in AD was late eczematous, rather than IgE mediated. Among eczematoid AD patients, 44.9% had high eosinophil levels. In patients with eczematoid AD, the food allergy prevalence was 70.8% (85/120) in the high eosinophil group and 34.7% (50/144) in the normal blood eosinophil group. An elimination diet improved clinical severity and decreased blood eosinophil levels. In milk allergy patients, a milk challenge significantly increased the blood eosinophil level. Skin-prick tests and food-specific IgE tests were useful for diagnosing IgE-mediated food allergy. Eosinophilia appeared to be a significant predictor of food allergy in AD and an indicating factor for diet manipulation, including an elimination diet. Food allergy may be responsible for eosinophilia in AD. Food allergy patterns for AD in Korea were different from those in western countries.


Subject(s)
Dermatitis, Atopic/diagnosis , Dermatitis, Atopic/epidemiology , Eosinophilia , Milk Hypersensitivity/diagnosis , Milk Hypersensitivity/epidemiology , Adolescent , Adult , Child , Child, Preschool , Dermatitis, Atopic/blood , Dermatitis, Atopic/diet therapy , Dermatitis, Atopic/physiopathology , Feeding Behavior , Female , Humans , Immunization , Immunoglobulin E/blood , Infant , Infant, Newborn , Korea , Male , Milk Hypersensitivity/blood , Milk Hypersensitivity/diet therapy , Milk Hypersensitivity/physiopathology , Predictive Value of Tests , Prevalence , Prognosis , Skin Tests
12.
Cell Immunol ; 262(1): 44-51, 2010.
Article in English | MEDLINE | ID: mdl-20079488

ABSTRACT

B cells have regulatory functions in immune responses. Antigen-specific responses of B cell subsets by allergen stimulation ex vivo were examined in milk allergy of late eczematous reactions. Eight milk allergy subjects and 13 milk tolerant subjects were selected by DBPCFC. PBMCs were stimulated by casein ex vivo and stained for B cell subsets using monoclonal antibodies. CD19+ B cells unchanged from 8.7+/-3.8% to 8.0+/-5.1% (p=0.504, n=8) in the milk allergy group and decreased in the milk tolerant group from 8.5+/-3.2% to 5.0+/-1.6% (p=0.001, n=13). The fraction of apoptotic B cells in B cells significantly decreased 4.4+/-3.1% to 1.3+/-0.4% (p=0.027, n=4) in the allergy group and insignificantly increased from 2.8+/-0.6% to 5.4+/-2.6% (p=0.059, n=6) in the milk tolerant group. CD5+ regulatory B1 cell% in B cells decreased in milk allergy subjects from 36.2+/-5.0% to 31.0+/-5.7% (p=0.010) and unchanged in milk tolerant subjects from 41.6+/-10.2% to 43.8+/-10.0% (p=0.413). IL-10 producing CD19+CD5+ regulatory B cell% in CD19+CD5+ regulatory B cells significantly decreased from 24.9+/-6.5% to 13.8+/-5.6% (p=0.002, n=5) by casein stimulation in milk allergy group and unchanged from 44.8+/-11.3% to 43.9+/-10.0% (p=0.297, n=5) in the milk tolerant group. B cell subset responses to IL-4 and IL-5 were also similar in both groups. B cell subset changes seemed to have diagnostic value. Exact immunologic roles of regulatory CD5+ B1 cells need further investigation.


Subject(s)
Allergens/immunology , B-Lymphocyte Subsets/immunology , Dermatitis, Atopic/immunology , Eczema/immunology , Milk Hypersensitivity/immunology , Milk/immunology , Animals , Antigens, CD19/immunology , Apoptosis , B-Lymphocyte Subsets/pathology , CD5 Antigens/immunology , Caseins/immunology , Child , Dermatitis, Atopic/pathology , Eczema/pathology , Female , Humans , Interleukin-10/biosynthesis , Interleukin-10/immunology , Interleukin-4/immunology , Interleukin-5/immunology , Male , Time Factors
13.
J Interferon Cytokine Res ; 29(10): 667-75, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19642905

ABSTRACT

Food-induced anaphylaxis is a life-threatening, IgE-mediated disease. No specific therapeutic recommendations, aside from the avoidance of offending foods, exist at this time. However, specific oral tolerance induction for food allergy has been investigated by several groups. In this study, specific oral tolerance induction was attempted using interferon-gamma (IFN-gamma) as an adjuvant for IgE-mediated anaphylactic food allergies. A total of 25 patients with IgE-mediated anaphylactic food allergy to milk, eggs, or wheat were selected. IFN-gamma-induced specific oral tolerance induction (ISOTI) was conducted on 10 patients, while five patients were only treated with food, five patients received only IFN-gamma therapy, and five patients did not receive any treatment. Tolerance for IgE-mediated anaphylactic food allergy was successfully induced in all patients (10/10) with ISOTI, while no patients acquired tolerance for allergenic foods in the control groups. Food-specific IgE levels were increased, and skin prick test reactions significantly decreased after the completion of ISOTI. IFN-gamma-induced specific oral tolerance induction (ISOTI) is a promisingly effective treatment for IgE-mediated anaphylactic food allergy. IFN-gamma may be an important cytokine in tolerance induction. Simultaneous allergen stimulation with nonspecific immunomodulation of IFN-gamma was essential for specific tolerance induction in IgE-mediated anaphylactic food allergy.


Subject(s)
Food Hypersensitivity/prevention & control , Immune Tolerance/drug effects , Immunoglobulin E/immunology , Interferon-gamma/therapeutic use , Administration, Oral , Case-Control Studies , Child , Child, Preschool , Desensitization, Immunologic/methods , Egg Hypersensitivity/immunology , Egg Hypersensitivity/prevention & control , Female , Food Hypersensitivity/immunology , Humans , Interferon-gamma/administration & dosage , Interferon-gamma/immunology , Male , Milk Hypersensitivity/immunology , Milk Hypersensitivity/prevention & control , Pilot Projects , Skin Tests , Treatment Outcome , Wheat Hypersensitivity/immunology , Wheat Hypersensitivity/prevention & control
14.
Appl Opt ; 48(11): 2165-70, 2009 Apr 10.
Article in English | MEDLINE | ID: mdl-19363556

ABSTRACT

We suggest a compact and efficient duplexer using the multimode interference (MMI) effect and the extraneous self-imaging phenomenon for gigabit-capable passive optical network and gigabit Ethernet passive optical network applications. To experimentally evaluate the suggested duplexer, silica-based MMI couplers were tested using light sources with wavelengths of 1310 and 1490 nm. From the experimental results, this device showed relative output powers of -0.3 and -0.7 dBm for the light sources with 1490 and 1310 nm wavelengths, respectively. The return power was measured to be less than -40 dBm.

15.
FEMS Microbiol Ecol ; 65(2): 339-49, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18631176

ABSTRACT

A set of PCR primers that should amplify all subgroups of arbuscular mycorrhizal fungi (AMF, Glomeromycota), but exclude sequences from other organisms, was designed to facilitate rapid detection and identification directly from field-grown plant roots. The small subunit rRNA gene was targeted for the new primers (AML1 and AML2) because phylogenetic relationships among the Glomeromycota are well understood for this gene. Sequence comparisons indicate that the new primers should amplify all published AMF sequences except those from Archaeospora trappei. The specificity of the new primers was tested using 23 different AMF spore morphotypes from trap cultures and Miscanthus sinensis, Glycine max and Panax ginseng roots sampled from the field. Non-AMF DNA of 14 plants, 14 Basidiomycota and 18 Ascomycota was also tested as negative controls. Sequences amplified from roots using the new primers were compared with those obtained using the established NS31 and AM1 primer combination. The new primers have much better specificity and coverage of all known AMF groups.


Subject(s)
DNA Primers/genetics , Fungi/classification , Fungi/isolation & purification , Mycorrhizae/classification , Mycorrhizae/isolation & purification , Polymerase Chain Reaction/methods , Ascomycota/classification , Ascomycota/genetics , Basidiomycota/classification , Basidiomycota/genetics , Fungi/genetics , Genes, rRNA , Molecular Sequence Data , Mycorrhizae/genetics , Phylogeny , Plants/classification , Plants/microbiology , Sensitivity and Specificity , Sequence Analysis, DNA
16.
Opt Lett ; 32(10): 1311-3, 2007 May 15.
Article in English | MEDLINE | ID: mdl-17440571

ABSTRACT

We discuss a self-imaging phenomenon in a multimode interference (MMI) coupler. From experiment, different self-images, which are undefined in MMI theory, are observed. These undefined self-images are named "extraneous self-images" (Ex_SIs) for convenience. To estimate the applicability of the Ex_SIs, the characteristics of both the single self-image (0 dB self-image, 0 dB SI), which is defined in MMI theory, and the Ex_SI are compared and analyzed through simulation and experiment. The results show that the Ex_SI has an imaging period that is the same as the 0 dB SI and that the excess loss and the extinction ratio of the Ex_SI improve more than that of the 0 dB SI as the imaging period increases.

17.
Pediatr Allergy Immunol ; 18(1): 63-70, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17295801

ABSTRACT

Food is closely associated with the pathogenesis of atopic dermatitis. Food allergy is usually mediated by IgE antibody to specific food proteins and determination of specific IgE antibody is the basis of the common diagnostic test for food allergy. IgG4 have been reported as blocking antibody and the protective effects of blocking antibody may be clear in inhalant allergy. However, the role of IgG4 in food allergy is still a matter of debate. In this study, the clinical significance of food allergen-specific IgE/IgG4 in atopic dermatitis was investigated and compared with that of IgE. A total of 97 patients who fulfilled the diagnostic criteria for atopic dermatitis participated in this study. Skin prick test and allergy patch test were performed. Specific IgE and IgG4 concentration were measured using allergy protein chip, 'AllergyChip'. Double blinded placebo controlled food challenge test (DBPCFC) was performed for the diagnosis of allergy to milk, egg white, wheat, and soybean. DBPCFCs for milk, egg white, soybean, and wheat were performed. The positive rates were 31.7% (19/60) in milk, 36.7% (18/49) in egg white, 30.4% (7/23) in soybean, and 34.8% (8/23) in wheat. Mean IgE/IgG4 levels in DBPCFC (+) subjects is higher than those in DBPCFC (-) subjects in all food items studied. Of them, there were significantly different between two groups in egg white and wheat (Egg white in DBPCFC (+) vs. (-): 0.4 +/- 0.3 vs. 0.2 +/- 0.2, wheat in DBPCFC (+) vs. (-): 1.2 +/- 1.2 vs. 0.3 +/- 0.3, p < 0.05). Allergen-specific IgE/IgG4 may provide one of the clues to understand the mechanism of food allergy in atopic dermatitis. The present study suggests that protein microarray can be one of the useful methods to assess ongoing status of allergic diseases.


Subject(s)
Dermatitis, Atopic/immunology , Food Hypersensitivity/immunology , Immunoglobulin E/immunology , Immunoglobulin G/immunology , Protein Array Analysis/methods , Adolescent , Adult , Allergens/administration & dosage , Allergens/immunology , Child , Child, Preschool , Dermatitis, Atopic/diagnosis , Dermatitis, Atopic/etiology , Double-Blind Method , Female , Food Hypersensitivity/diagnosis , Food Hypersensitivity/etiology , Humans , Male , Skin Tests
18.
J Virol Methods ; 133(1): 27-33, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16300838

ABSTRACT

Porcine epidemic diarrhea virus (PEDV), a member of the family Coronaviridae, has caused a devastating enteric disease in the Korean swine industry. Previously, the differences between virulent field PEDV strains and a Vero cell culture adapted PEDV DR13 strain were determined using restriction fragment length polymorphism analysis (RFLP), and PEDV shedding patterns in pigs were reported. In an extension to these studies, an internal control was constructed and quantitative analysis of virus shedding after oral inoculation was established. A parent field PEDV and a cell culture adapted PEDV DR13 were inoculated orally to colostrum-deprived 1-day-old piglets, commercial 2-week-old pigs, and sows (1-5 ml dose, 10(5.8)-10(6.0) TCID(50)/0.1 ml). PEDV shedding was monitored every day and virus levels were measured using a quantitative reverse transcriptase polymerase chain reaction (RT-PCR) method. In fecal samples from experimentally-inoculated pigs, the level of virus excreted peaked at 2 days after oral inoculation and gradually decreased thereafter. In addition, PEDV from field specimens was quantified using the same RT-PCR assay to determine shedding viral load. This suggests that measurement of PEDV shedding viral load in pigs, by quantitative RT-PCR, may be a useful tool for estimating the transmission potential of PEDV in the swine population.


Subject(s)
Coronaviridae Infections/veterinary , Coronaviridae/isolation & purification , Gastroenteritis, Transmissible, of Swine/virology , RNA, Viral/analysis , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Animals , Chlorocebus aethiops , Coronaviridae/genetics , Coronaviridae Infections/diagnosis , Coronaviridae Infections/virology , DNA, Complementary , Feces/virology , Gastroenteritis, Transmissible, of Swine/diagnosis , Gastroenteritis, Transmissible, of Swine/genetics , Polymorphism, Restriction Fragment Length , RNA, Viral/genetics , Reference Standards , Swine , Swine Diseases/diagnosis , Swine Diseases/virology , Vero Cells , Viral Load , Virus Shedding
19.
Yonsei Med J ; 43(5): 613-20, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12402374

ABSTRACT

Skin Prick Test (SPT's) are performed to identify the causes of allergy. However, low diagnostic accuracy is a limitation to SPT, for which many possible causes have been suggested. The protein composition and allergenicity of crude allergen extracts from foods and commercial allergen extracts for SPT were analyzed. Clinical significances of SPT using crude allergen extracts from foods were compared with those using commercial allergen extracts. A total of 292 atopic dermatitis patients were involved in this study. Crude allergen extracts were prepared from milk, egg white, egg yolk, and soybean. The protein composition of food allergen extracts and commercial allergen extracts of milk, whole egg, white, egg yolk, and soybean were compared by SDS-PAGE. The allergenicity was tested by the immunoblotting method using immune sera. SPTs were performed using crude and commercial allergen. Double-blind placebo- controlled food challenge (DBPCFC) was performed to verify the SPT results and to compare the clinical significance of crude and commercial allergen extracts. Protein composition differed markedly between crude and commercial allergen extracts. By immunoblotting, crude and commercial allergen extracts showed different allergenicity. The SPT results using crude and commercial allergen extracts showed significant differences. The prevalence of milk, egg and soybean allergy was over 35% in atopic dermatitis. The accuracy of SPT using crude allergen extracts from foods was significantly higher than that using commercial allergen extracts. In the case of soybeans, the result of SPT using commercial allergen extract was clinically insignificant for the prediction of soybean allergy. The source of allergen extract was very important for the appropriate SPT in food allergy. The accuracy of SPT might be improved using the appropriate allergen source for food allergy.


Subject(s)
Allergens/immunology , Dermatitis, Atopic/immunology , Egg Hypersensitivity/diagnosis , Food Hypersensitivity/diagnosis , Glycine max/immunology , Milk Hypersensitivity/diagnosis , Adolescent , Adult , Child , Child, Preschool , Double-Blind Method , Female , Humans , Male , Placebos , Skin Tests
20.
Exp Mol Med ; 34(2): 152-8, 2002 May 31.
Article in English | MEDLINE | ID: mdl-12085991

ABSTRACT

Type I allergy is an immunoglobulin E (IgE)-mediated hypersensitivity disease inflicting more than quarter of the world population. In order to identify allergen sources, skin provocation test and IgE serology was performed using allergen extracts. Such process identifies allergen-containing sources but cannot identify the disease-eliciting allergenic molecules. Recently, microarray technology has been developed for allergen-specific IgE detection using rolling circle amplification. This study was carried out to evaluate protein chip technology for the quantitative measurement and limits of sensitivity of multiple allergen-specific IgE by an immunofluorescence assay. Significance of positive calibrators was tested using purified human IgE. Dermatophagoides pteronyssinus (Dp), egg white, milk, soybean, and wheat were used as allergens and human serum albumin as negative control. Sensitivity and clinical efficacy of protein chip were evaluated using allergy immune serum for Dp. The fluorescent intensities for purified human IgE as calibrator were well correlated with the concentrations of human IgE. Two-fold dilution of serum allowed an optimal reaction with Dp (1 mg/ml) at which serum Dp-specific IgE levels by protein chip were compatible with those by UniCap. The sensitivity of protein chip in this study was found at level of 1 IU/ml of IgE. Dp-specific IgE levels by protein chip correlated well with those of UniCap by comparing 10 atopic dermatitis. Additional 18 sera were tested for above multiple antigens other than Dp and significant results were obtained for many antigens as well as Dp. These results indicated that spotting of heterogeneous protein mixture on protein chip and the quantitative measurement of serum allergen-specific IgE levels using immunofluorescence assay can be successfully applied in the clinical laboratory for the diagnosis of allergy and could be applied to diagnosis of autoimmune and infectious diseases


Subject(s)
Fluorescent Antibody Technique/methods , Immunoglobulin E/blood , Protein Array Analysis/methods , Allergens/immunology , Antibody Specificity , Dermatitis, Atopic/immunology , Humans , Immunoglobulin E/immunology , Korea , Sensitivity and Specificity
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